[turbofan] Rewrite ToObject as TurboFan stub.

src/builtins/mips/builtins-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 2395 matching lines @@
       }
       __ bind(&convert_to_object);
       {
         // Convert receiver using ToObject.
         // TODO(bmeurer): Inline the allocation here to avoid building the frame
         // in the fast case? (fall back to AllocateInNewSpace?)
         FrameScope scope(masm, StackFrame::INTERNAL);
         __ sll(a0, a0, kSmiTagSize);  // Smi tagged.
         __ Push(a0, a1);
         __ mov(a0, a3);
+        __ Push(cp);
         ToObjectStub stub(masm->isolate());
         __ CallStub(&stub);
+        __ Pop(cp);
         __ mov(a3, v0);
         __ Pop(a0, a1);
         __ sra(a0, a0, kSmiTagSize);  // Un-tag.
       }
       __ lw(a2, FieldMemOperand(a1, JSFunction::kSharedFunctionInfoOffset));
       __ bind(&convert_receiver);
     }
     __ Lsa(at, sp, a0, kPointerSizeLog2);
     __ sw(a3, MemOperand(at));
   }
@@ skipping 573 matching lines @@
     __ break_(0xCC);
   }
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS